NEET Wave Optics — Set 15

Question 1

What is the direction of the electric field in a linearly polarized light wave relative to its propagation direction?

Accepted Answer

In a linearly polarized light wave, the electric field oscillates perpendicular to the direction of propagation.

Question 2

What is the resultant amplitude of two coherent waves of amplitude $ a $ with a phase difference of $ 5\pi/2 $?

Accepted Answer

Resultant amplitude $ A = 2a \cos(\phi/2) $. For $ \phi = \frac{5\pi}{2} $, $ A = 2a \cos\left(\frac{5\pi}{4}\right) = 2a \left(-\frac{\sqrt{2}}{2}\right) = -a\sqrt{2} $, magnitude $ a\sqrt{2} $.

Question 3

What causes the intensity of light to remain conserved during interference despite the presence of dark fringes?

Accepted Answer

Energy is redistributed from dark to bright fringes through interference, conserving total energy as the sum of intensities balances out.

NEET Physics: Wave Optics — Practice Set 15

Q1. What is the direction of the electric field in a linearly polarized light wave relative to its propagation direction?

Q2. What is the resultant amplitude of two coherent waves of amplitude \( a \) with a phase difference of \( 5\pi/2 \)?

Q3. What causes the intensity of light to remain conserved during interference despite the presence of dark fringes?

Q4. What is the intensity at a point in a double-slit experiment where the path difference is \( 5\lambda/2 \), if the maximum intensity is \( 4I_0 \)?

Q5. What is the angular position of the third minimum in a single-slit diffraction pattern if the slit width is \( 4.0 \, \mu\text{m} \) and the wavelength is \( 400 \, \text{nm} \)?

Q6. What is the angular width of the central maximum in a single-slit diffraction pattern if the slit width is \( 5.0 \, \mu\text{m} \) and the wavelength is \( 650 \, \text{nm} \)?

Q7. What is the intensity at a point in a double-slit experiment where the path difference is \( 7\lambda/2 \), if the maximum intensity is \( 4I_0 \)?

Q8. What is the angular position of the third minimum in a single-slit diffraction pattern if the slit width is \( 10.0 \, \mu\text{m} \) and the wavelength is \( 600 \, \text{nm} \)?

Q9. What is the intensity of light after passing through three polaroids, with the first and third crossed and the second at \( 45^\circ \) to the first, if the initial unpolarized intensity is \( I_0 \)?

Q10. What is the phase difference corresponding to a path difference of \( 5\lambda/4 \) in a double-slit experiment?